================================================================================ IBIS INTERCONNECT TASK GROUP https://urldefense.proofpoint.com/v2/url?u=http-3A__www.ibis.org_interconnect-5Fwip_&d=DwIGAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=DcQR-qLpQg5lIreuM6-NYECRIAFXt268PRNS5WO043M&m=Dyw6fgDRnU3hKhF501JLjKMYzgRJA5f0_BDjinAWJqhP-QqSt2v48hlBnUQVgCdo&s=lzNRzahKKBXPxk_YU-FxfbhsNnO-p6JPfC6lgQDsDyU&e= Mailing list: ibis-interconnect@freelists.org Archives at https://urldefense.proofpoint.com/v2/url?u=http-3A__www.freelists.org_archive_ibis-2Dinterconn_&d=DwIGAg&c=nKjWec2b6R0mOyPaz7xtfQ&r=DcQR-qLpQg5lIreuM6-NYECRIAFXt268PRNS5WO043M&m=Dyw6fgDRnU3hKhF501JLjKMYzgRJA5f0_BDjinAWJqhP-QqSt2v48hlBnUQVgCdo&s=aLvA3ynmxT1bO5-wuwfASjI1u-TNK-TkBLtyVK5i8HE&e= ================================================================================ Attendees from August 10, 2022 Meeting (* means attended at least using audio) ANSYS Curtis Clark Intel Corp. Michael Mirmak* Michael Brownell* Keysight Technologies Ming Yan* Marvell Steve Parker MathWorks Walter Katz Micron Technology Justin Butterfield* Randy Wolff* Siemens EDA Arpad Muranyi* ST Microelectronics Aurora Sanna Teraspeed Labs Bob Ross* University of Illinois Jose Schutt-Aine Zuken USA Lance Wang* Michael Mirmak convened the meeting. No patents were declared. Justin Butterfield took minutes. Review of Minutes: - Michael called for review of the minutes from the July 27, 2022 meeting. Michael displayed the minutes. Randy Wolff moved to approve the minutes. Lance Wang seconded. The minutes were approved without objection. Review of ARs: - Arpad Muranyi to give an example of the physical connectivity needed for EMD automation [AR]. - Michael suggest to keep this open. - Arpad and Randy to review the intermingled text between Touchstone 1 and Touchstone 2 sections [AR]. - Michael suggest to keep this open. - Michael will send out draft 2 of the outline. - Done. Opens: - Michael would like to review the ISSIRD for adding the S-parameter scaling support in the IBIS-ISS W-element. - Randy noted there is not much to discuss on the draft separating Touchstone 1 and 2. Bob Ross commented there is no official Touchstone 1.0 document, only Touchstone 2 is the official record. Arpad asked if the Touchstone 1.1 is different from Touchstone 1. Bob replied it is. Michael asked if the differences are known. Bob replied Touchstone 1.1 was an edited version from the original Touchstone 1 from Agilent. Arpad asked if there is no official Touchstone 1 document why are we referencing it. Randy suggested we could change how we reference it. Michael noted we could retroactively issue a Touchstone 1, and we should have the original document. Randy stated he has not seen that document. Michael will search for the original Agilent Touchstone 1 document. Discussion: ISSIRD1 Draft1: Michael noted there is a significant gap in IBIS-ISS from Synopsys HSPICE, where IBIS-ISS does not allow the W-element support of S-parameters. The RLGC Model and Table Model formats are supported. HSPICE has the ability to scale the S-parameter in the W-element with a length factor. The ISSIRD proposes to add this support to the W-element. He copied the relevant test from the HSPICE manual to support this format. Arpad asked if the length value can be an integer or any floating point number. Michael would have to check. Arpad asked if we need to get permission from Synopsys to use this text. Michael replied it would be a good idea. He noted he did not copy from the HSPICE manual exactly, but he did follow the concept of this feature. Arpad asked if it is okay to use the concept of this feature. Michael will check with Synopsys if they are okay with using this implementation in IBIS-ISS. Bob asked why not copy the text exactly. Michael replied the text requires some careful editing, as there are many other features in the HSPICE W-element that we do not support. Michael asked if we know of any EDA tools that do not support this format. Arpad replied he will have to check on his tool's support for this. Bob noted some tools may support it in an HSPICE compatibility mode. Arpad noted it is easy to cascade S-parameters if the length is forced to be an integer, but if the length can be any factor, then there would need to be additional processing on the EDA tool side. Arpad asked if there are any restrictions on the S-parameters, such as S-parameters that are not reciprocal. Michael was not sure how these cases are handled. Arpad noted it could be difficult if the S-parameter models are for tapered traces, for instance. He asked how this feature is implemented, if the S-parameters are cascaded, or if there is some numerical manipulation. Randy suggested there would have to be some assumptions. Michael suggested to invite Synopsys to this meeting to see if they are willing to discuss the preferred limitations of the S-parameters that can be used by this feature. Randy noted this is a W-element and the S-parameter should be of a transmission line structure and not any arbitrary structure, such as those with impedance discontinuities. Michael noted the W-element length in IBIS-ISS can be any number and is not required to be an integer. Michael noted there is an "XLINELENGTH" parameter in this format which is the extracted length of the S-parameter model used by the W-element. Michael noted there are other features in HSPICE such as Mixed Mode and "fmax", which he did not add in as new features to IBIS-ISS. He asked if these are something we want to support. Randy asked if these are supported in the S-element. Michael reviewed the IBIS-ISS specification and reported these are not supported. Michael will check with Synopsys on permission for using the W-element S-parameter feature and what they can share on algorithm details and model restrictions [AR]. Draft separating Touchstone 1 and 2: Arpad asked what version the separation draft should use as the baseline. Randy noted there was a draft 10 that included the TSIRD3 and TSIRD4 changes, and he suggested to start working with this. Michael asked if we need to have the separation draft done before we start to write Touchstone 3. Arpad thought this is the direction that we wanted to go. We will still need the separation draft if we want to reorganize the document based on the outline. Bob agreed that we need to do the separation, and we should document Touchstone 1 completely. Michael asked if we should use the outline to guide the separation or use the separation to guide the outline. Arpad suggested to do the separation then get agreement it is good. Meeting schedule: Arpad asked if the Editorial task group would use this time slot and give more time to work on the separation draft while IBIS 7.2 editorial work is ongoing. Michael noted we will vote on the technical content and discuss the task group schedule in the Open Forum meeting on Friday. Randy noted the priority, as discussed in the last Open Forum meeting, is to get the IBIS 7.2 specification released. Michael asked if we will have any topics to discuss in this next week. Bob replied we have the ISSIRD to work on. Michael was not sure how soon he can get feedback from Synopsys on the open questions. Michael suggested to note the remaining open agenda topics. Open topics remaining on the agenda: - Touchstone 1 and 2 separation draft - ISSIRD1 Draft - Touchstone 3.0 draft outline - Touchstone 2.0 with TSIRD3 and TSIRD4 draft - Pole-residue format BIRD draft - Port naming proposal Arpad moved to suspend the Interconnect meeting pending the outcome of the Open Forum vote on IBIS 7.2 technical content. Randy seconded. There were no objections. Arpad moved to cancel next week's meeting. Randy seconded. No objections. Arpad moved to adjourn. Randy seconded. Next Meeting: The next meeting will be TBD. ================================================================================ Bin List: 1. Touchstone 3 2. Pole-residue support for Touchstone 3. Port naming